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Local structure of DNA toroids reveals curvature-dependent intermolecular forces
In viruses and cells, DNA is closely packed and tightly curved thanks to polyvalent cations inducing an effective attraction between its negatively charged filaments. Our understanding of this effective attraction remains very incomplete, partly because experimental data is limited to bulk measureme...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Oxford University Press
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8053110/ https://www.ncbi.nlm.nih.gov/pubmed/33784405 http://dx.doi.org/10.1093/nar/gkab197 |
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author | Barberi, Luca Livolant, Françoise Leforestier, Amélie Lenz, Martin |
author_facet | Barberi, Luca Livolant, Françoise Leforestier, Amélie Lenz, Martin |
author_sort | Barberi, Luca |
collection | PubMed |
description | In viruses and cells, DNA is closely packed and tightly curved thanks to polyvalent cations inducing an effective attraction between its negatively charged filaments. Our understanding of this effective attraction remains very incomplete, partly because experimental data is limited to bulk measurements on large samples of mostly uncurved DNA helices. Here we use cryo electron microscopy to shed light on the interaction between highly curved helices. We find that the spacing between DNA helices in spermine-induced DNA toroidal condensates depends on their location within the torus, consistent with a mathematical model based on the competition between electrostatic interactions and the bending rigidity of DNA. We use our model to infer the characteristics of the interaction potential, and find that its equilibrium spacing strongly depends on the curvature of the filaments. In addition, the interaction is much softer than previously reported in bulk samples using different salt conditions. Beyond viruses and cells, our characterization of the interactions governing DNA-based dense structures could help develop robust designs in DNA nanotechnologies. |
format | Online Article Text |
id | pubmed-8053110 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Oxford University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-80531102021-04-21 Local structure of DNA toroids reveals curvature-dependent intermolecular forces Barberi, Luca Livolant, Françoise Leforestier, Amélie Lenz, Martin Nucleic Acids Res Chemical Biology and Nucleic Acid Chemistry In viruses and cells, DNA is closely packed and tightly curved thanks to polyvalent cations inducing an effective attraction between its negatively charged filaments. Our understanding of this effective attraction remains very incomplete, partly because experimental data is limited to bulk measurements on large samples of mostly uncurved DNA helices. Here we use cryo electron microscopy to shed light on the interaction between highly curved helices. We find that the spacing between DNA helices in spermine-induced DNA toroidal condensates depends on their location within the torus, consistent with a mathematical model based on the competition between electrostatic interactions and the bending rigidity of DNA. We use our model to infer the characteristics of the interaction potential, and find that its equilibrium spacing strongly depends on the curvature of the filaments. In addition, the interaction is much softer than previously reported in bulk samples using different salt conditions. Beyond viruses and cells, our characterization of the interactions governing DNA-based dense structures could help develop robust designs in DNA nanotechnologies. Oxford University Press 2021-03-30 /pmc/articles/PMC8053110/ /pubmed/33784405 http://dx.doi.org/10.1093/nar/gkab197 Text en © The Author(s) 2021. Published by Oxford University Press on behalf of Nucleic Acids Research. https://creativecommons.org/licenses/by-nc/4.0/This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (http://creativecommons.org/licenses/by-nc/4.0/ (https://creativecommons.org/licenses/by-nc/4.0/) ), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com |
spellingShingle | Chemical Biology and Nucleic Acid Chemistry Barberi, Luca Livolant, Françoise Leforestier, Amélie Lenz, Martin Local structure of DNA toroids reveals curvature-dependent intermolecular forces |
title | Local structure of DNA toroids reveals curvature-dependent intermolecular forces |
title_full | Local structure of DNA toroids reveals curvature-dependent intermolecular forces |
title_fullStr | Local structure of DNA toroids reveals curvature-dependent intermolecular forces |
title_full_unstemmed | Local structure of DNA toroids reveals curvature-dependent intermolecular forces |
title_short | Local structure of DNA toroids reveals curvature-dependent intermolecular forces |
title_sort | local structure of dna toroids reveals curvature-dependent intermolecular forces |
topic | Chemical Biology and Nucleic Acid Chemistry |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8053110/ https://www.ncbi.nlm.nih.gov/pubmed/33784405 http://dx.doi.org/10.1093/nar/gkab197 |
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